My Science School

Lemurs are 100 or so species of primates in Madagascar. The name lemur derives from the Latin word lemures, which some dictionaries translate as ghosts. In Ancient Rome, lemures were believed to be a kind of eerie-looking malignant dead that wandered the earth at night, causing hurt and injury to the living. It is believed that the name got attached to the primates because of their reflective eyes and their silent nocturnal wanderings.

A number of lemurs are rare or endangered. Several either were not discovered until the late 20th century or were rediscovered after having been thought extinct. Remains exist of species larger than any of today’s lemurs. Some of these may have survived until only 500 years ago. They were probably exterminated by overhunting or habitat modification by the Malagasy people, who arrived on the island less than 2,000 years ago.

Lemurs are less intelligent than monkeys. Their sense of smell is more acute but their vision less so. Although some species are at times active during the day, their eyes seem to be adapted for nocturnal life, trading acuity for increased sensitivity in low light conditions. All lemurs are characterized by a reflective layer (tapetum) behind the retina in the eye, but no fovea or macula lutea; a hairless, moist tip to the muzzle; a noninvasive (epitheliochorial) placenta; comblike forward-directed lower front teeth (with the exception of the aye-aye); and a claw (“toilet claw”) on the second toe of the foot.

Credit : Britannica

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The Tripod fish or the 'stilt walker' has modified pelvic and caudal fins that are elongated at the tips, called rays or elements. It uses these rays to perch on the deep sea floor. Scientists suspect that fluid is: pumped through the extremely long rays, making them rigid and allowing the fish to balance while "standing". As a result of living in virtually complete darkness, these eyeless fish have developed long pectoral fins that extend upward like antennae, and serve as tactile organs or hands, when it searches for food.

Tripod fish positions its body upstream, toward the water current and waits for the prey to come. Main purpose of elongated structures is to lift the fish from the ocean floor where water current doesn't exist. This tactic ensures preservation of energy (tripod fish doesn't move when hunts) and continual supplying with the prey (which ocean current brings).

Tripod fish possesses long, feathery pectoral fins that are used as tactile organ. They float in front of the fish and detect movement of the water and potential prey. When edible prey is detected, tripod fish catches it and transports it directly into the mouth (these fins are also used as hands).

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Gastrodia agnicellus is the 'ugliest orchid in the world' according to the Royal Botanical Gardens, Kew (U.K.). Native to Madagascar, it grows underground in decaying leaf litter for most of its life cycle. The fleshy brown flowers, which are probably pollinated by flies, measure less than half an inch and have a musk rose-like scent. The orchid depends on fungi for nutrition and has no leaves or any other photosynthetic tissue.

Orchids are fascinating and there are so many variants of the flower species. The latest discovery challenges the usual approach of orchids being a delicate flower species. The blooms are often colourful and fragrant, but the latest one is described ugliest because of its appearance and flesh nature. Although assessed as a threatened species, the plants have some protection because they are located in a national park. The flowers, too, are small—just 11 millimetres in length, ranging from brown to white in colour. No one realised the significance until recently.

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The Bee Hummingbird or Helena hummingbird (Mellisuga helenae) is the world's smallest bird measuring 24 inches long and weighing 1.98 gms. It is close in size to a large bee and hence its name. The female builds a nest barely an inch across, and her egg measures 0.275 inches long, making it the smallest egg laid by any bird. In flight, the Bee Hummingbird's tiny wings beat 80 times a second, and during a courtship flight, up to 200 times per second!

The male has a green pileum and bright red throat, iridescent gorget with elongated lateral plumes, bluish upper parts, and the rest of the underparts mostly greyish white. Compared to other small hummingbirds, which often have a slender appearance, the bee hummingbird looks rounded and plump.

Female bee hummingbirds are bluish green with a pale gray underside. The tips of their tail feathers have white spots. During the mating season, males have a reddish to pink head, chin, and throat. The female lays only two eggs at a time, each about the size of a coffee bean.

The brilliant, iridescent colors of the bee hummingbird's feathers make the bird seem like a tiny jewel. The iridescence is not always noticeable, but depends on the viewing angle. The bird's slender, pointed bill is adapted for probing deep into flowers. The bee hummingbird feeds mainly on nectar, by moving its tongue rapidly in and out of its mouth. In the process of feeding, the bird picks up pollen on its bill and head. When it flies from flower to flower, it transfers the pollen. In this way, it plays an important role in plant reproduction. In one day, the bee hummingbird may visit 1,500 flowers.

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Monarch butterflies embark on a marvelous migratory phenomenon. They travel between 1,200 and 2,800 miles or more from the United States and Canada to central Mexican forests. There the butterflies hibernate in the mountain forests, where a less extreme climate provides them a better chance to survive. 

Monarch caterpillars are striped with yellow, black, and white bands, and reach lengths of two inches (five centimeters) before metamorphosis. They have a set of antennae-like tentacles at each end of their body. The monarch chrysalis, where the caterpillar undergoes metamorphosis into the winged adult butterfly, is a beautiful seafoam green with tiny yellow spots along its edge.

Whether monarchs are present in a given area within their range depends on the time of year. They are one of the few migratory insects, traveling great distances between summer breeding habitat and winter habitat where they spend several months inactive. In the summer they range as far north as southern Canada. In the fall the eastern population migrates to the cool, high mountains of central Mexico and the western population migrates to coastal California, where they spend the entire winter.

The monarch population has declined by approximately 90 percent since the 1990s. Monarchs face habitat loss and fragmentation in the United States and Mexico. For example, over 90 percent of the grassland ecosystems along the eastern monarch’s central migratory flyway corridor have been lost, converted to intensive agriculture or urban development. Pesticides are also a danger. Herbicides kill both native nectar plants where adult monarchs feed, as well as the milkweed their caterpillars need as host plants. Insecticides kill the monarchs themselves. Climate change alters the timing of migration as well as weather patterns, posing a risk to monarchs during migration and while overwintering. The U.S. Fish & Wildlife Service is currently reviewing the species’ status.

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Whether delicately perched on a cattail or hovering over a pond, dragonflies are a sure sign of summer.

Living on every continent but Antarctica, these insects are instantly recognizable by their large bodies; four long, horizontal wings; and the way they hover and zip around. Dragonflies can reach speeds of up to 35 miles an hour and fly just as gracefully backward by lifting off vertically, helicopter style.

Dragonflies are important to their environments both as predators (particularly of mosquitos) and as prey to birds and fish. Because these insects require stable oxygen levels and clean water, scientists consider them reliable bioindicators of the health of an ecosystem.

In 2009, the first comprehensive assessment of insect species showed that 10 percent of dragonfly species were under threat of extinction. The animals are imperiled by destruction of freshwater habitats—particularly ponds, bogs, and fens—by pollution, and non-native vegetation.

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Sea turtles are reptiles remarkably suited to life in the sea. Their hydrodynamic shape, large size, and powerful front flippers allow them to dive to great depths and swim long distances. These front flippers are long, narrow, and winglike, while their hind flippers are shorter. Although sea turtles can remain submerged for hours at a time while resting or sleeping, they typically surface several times each hour to breathe.

Sea turtles are among the oldest creatures on Earth and have remained essentially unchanged for 110 million years. In most sea turtles, the top shell—or carapace—is composed of many bones covered with horny scales, or scutes. Unlike their terrestrial relatives, they cannot retract their heads into their shells. The smallest of the sea turtles are the two species of ridleys, weighing in at 85 to 100 pounds (38 to 45 kilograms) as adults. Leatherbacks are the biggest and can grow to 2,000 pounds (900 kilograms). Most sea turtles grow slowly and have a lifespan of many decades.

All sea turtles are threatened or endangered. They face an uncertain future due to threats of many kinds, including pollution and the encroachment of coastal development on their nesting beaches. They are also susceptible to accidental drowning in fishing gear and are at risk from the international trade in turtle meat and shell products.

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The crabs' breeding timetable is fixed around the phases of the moon. Spawning (the dropping of their eggs into the sea) must occur before sunrise on spring tides during the last quarter of the moon, regardless of any other factor. The timing of spawning is the only certain and predictable part of the whole migration; all other stages of the migration will vary with the prevailing weather.

The crabs will start their migration if there is enough time for them to complete their downward migration, mate and develop eggs before the next suitable spawning date.

The red crab breeding migration comprises a series of separate actions on the crabs' part that follow on from one to the other in a programmed sequence. These separate actions in combination make up the breeding migration and one action will not occur unless the preceding action is accomplished. If there isn't enough time for them to be able to do all of these things before the next spawning opportunity, they will delay the start of their migration and attempt to meet the following month's spawning date.

The red crab migration is Christmas Island’s biggest tourist attraction, drawing nature-lovers from all over the world.

The easiest places to watch the migration and spawning are Drumsite, Flying Fish Cove, Ethel Beach and Greta Beach.

To protect our red crabs, some sections of roads may close for part or all of the day during the peak migration time, often at short notice. But you can park your car and carefully walk among the sea of moving crabs as they make their way to and from the beach.

You will also see crab bridges built over the roads. These are great places to stand and watch the flow of crabs.

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The ungainly gnu (pronounced “g-new” or simply “new”) earned the Afrikaans name wildebeest, or “wild beast,” for the menacing appearance presented by its large head, shaggy mane, pointed beard, and sharp, curved horns.

Their habitat comprises the grassy plains and open woodlands of central, southern, and eastern Africa, particularly the Serengeti in Tanzania and Kenya. They travel in large herds and are active day and night, grazing constantly.

Up to 500,000 calves are born in February and March each year, at the beginning of the rainy season. Calves learn to walk within minutes of birth and within days are able to keep up with the herd. Wildebeests can live to be 20 years old.

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Moose is the largest of all the deer species. It inhabits forests during winter and areas near rivers and streams during summer. It is found all over the North hemisphere, mainly in the colder climate.

It has poor eyesight, but has excellent sense of smell and hearing. It is also an excellent swimmer and a fast runner.

One of its unique features is the antlers. Only male moose (bulls) sport antlers. The shape differs from animal to animal and they are shed every year around November, being replaced with larger ones the forthcoming spring. The primary function of antlers is to attract potential mate.

A male moose also has a ‘dewlap’, a dangling up under the chin.

Adult of its species are too big to have many predators, but bears, wolves, and cougars prey on calves.

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Snakes that lay their eggs outside of their bodies are known as oviparous. Those that retain them are called ovoviviparous. Ovoviviparous snakes appear to give birth to live young, but they actually don't -- although there are those who do, known as viviparous snakes.

While ovoviviparous snakes lay eggs, just like their oviparous counterparts, the mother snake simply keeps those eggs within her body while they incubate. Usually ovoviviparous species, such as some garter snakes and pit vipers, live in cooler climates where it would be harder for the mother snake to properly brood the eggs to keep them warm enough to hatch. By keeping them inside, she can maintain them at a comfortable temperature. Unlike viviparous species, there is no transfer of fluids between mother and babies, because they each feed on the substances contained in their individual eggs. Babies emerge from the mother when they hatch from their eggs, giving them the appearance of "live" births.

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Did you know that there are some snakes such as rattlesnakes, Russell’s vipers and boas that do not lay eggs? They give birth to baby snakes. In other words, the babies develop in their mother snake before emerging into this world. These snakes may be viviparous (no egg at any stage of development) or ovoviviparous (eggs hatched within the mother’s body). The baby snakes are independent from day one.

When baby snakes are born live, as is the case with viviparous and ovoviviparous species, they are completely on their own from day one! There is no parental protection in the snake world. The babies go off on their own shortly after birth, and must fend for themselves. That is why baby rattlesnakes are born "fully loaded" with fangs and venom.

Sea snakes are a mixed lot. They are members of Hydrophiinae, a subfamily of the Elapidae family that also includes the venomous cobras, adders and mambas. Most of the sea snake species give birth to live young, which means the babies are born alive in the water. But there is one genus, Laticauda, which is oviparous. The female members of this particular genus lay eggs on land, as opposed to giving live birth like the other sea snakes.

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A town in Washington has a treetop bridge for squirrels, named Nutty Narrows Bridge. Located in Longview, it looks like a tiny suspension bridge with its deck just wide enough for squirrel traffic. The bridge was built by one Amos J. Peters in 1963 to save squirrels from getting squashed by passing cars on the busy thoroughfare of Olympia Way.

The Nutty Narrows is locally significant to the city of Longview under Criterion A for entertainment/recreation due to its beloved status as a city icon and its provision of opportunity for wildlife viewing. The bridge represents the efforts of a small group of citizens who created a beloved community landmark to save local squirrels from having to cross a busy thoroughfare. The bridge has become a favorite local roadside attraction and has remained an important landmark in Longview, Washington. The Nutty Narrows Bridge is significant under the National Register eligibility Criterion A, for its entertainment/recreation related themes as a reflection of the development of the bridge to solve the burgeoning need for a safe passageway for the city's squirrel population over Olympia Way in Longview, Washington. The period of significance begins and ends in 1963, the year of construction. Amos Peters, the bridge's designer and constructor, discovered the need for the bridge when he noticed a red squirrel in the road in front of his office building that had met a vehicular demise. Peters envisioned the bridge and then, by constructing it, created one of the most beloved novelty attractions in Longview. After the construction of the Nutty Narrows Bridge, a large squirrel statue was constructed in Amos Peters' memory in a nearby park and four other squirrel bridges have since been constructed within the Longview city limits.

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Every gardener knows that slugs and snails are active in warm weather and absent in cold weather. They come out after it rains or when plants are watered. This makes it the best time to put out your slug and snail pellet baits. They hibernate or die during heat and drought. Snails and slugs are more active on cloudy days and less active on sunny days.

You can use the aversion of slugs and snails to heat and cold to trap them for easy disposal. In hot weather, dampen the ground in a corner of your garden and cover it with plywood or a flower pot turned upside down. Slugs and snails will gather in the damp, cooler haven you provide them so you can more easily kill or remove them from your property.

You can also kill slugs and snails with cold. Let them find a winter home under a pile of leaves or a piece of plywood, and then remove their cover the first night you have a heavy frost. The cold will take care of your infestation with no need of toxic chemicals or tedious picking by hand.

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It is a misconception that slugs have four noses. These slimy creatures have two retractable pairs of tentacles. They use the upper tentacles for seeing and smelling. These eye-stalks can function independently and can be regenerated if lost. The smaller, lower tentacles are used for feeling and tasting. Slugs eat using a radula, a tongue-like organ covered with thousands of sharp protrusions. Many species of slugs play an important role in the ecosystem by feeding on decaying vegetation.

Slugs also have thousands and thousands of teeth. These tiny chompers are part of a rasping structure called a radula that’s unique to mollusks. And in case that doesn't seem weird enough, slugs essentially breathe through a blowhole that opens up on one side of their bodies. This round pore is called a pneumostome.

But that’s just the anatomy of land-living slugs. Sea slugs have their own incredible features. For example, some breathe using delicate feather-like gills that surround their butt holes, and they smell with neon-colored, bizarrely shaped protrusions called rhinophores.

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